Satellite television
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Artist's impression of a Boeing 601 satellite, as configured for digital television transmission by SES Astra |
Satellite television is
television delivered by way of
communications satellites, as compared to conventional
terrestrial television and
cable television. In many areas of the world satellite television services supplement older terrestrial signals, providing a wider range of channels and services, including subscription-only services.
The first satellite television signal was relayed from
Europe to the
Telstar satellite over
North America in 1962. The first
geosynchronous communication satellite,
Syncom 2 was launched in 1963. The world's first commercial communication satellite, called
Early Bird, was launched into synchronous orbit on
April 6,
1965. The first national
network of satellite television, called
Orbita, was created in
Soviet Union in 1967, and was based on the principle of using the highly-elliptical
Molniya satellite for re-broadcasting and delivering of TV
signal to ground
downlink stations. The first domestic North American satellite to carry television was
Canada's geostationary
Anik 1, which was launched in 1973.
ATS-6, the world's first experimental educational and
Direct Broadcast Satellite, was launched in 1974. The first Soviet geostationary satellite to carry
Direct-To-Home television, called
Ekran, was launched in 1976.
Consumer satellite television reception in the United States began in the early 1980's with the introduction of the first home satellite systems designed for receiving the same TVRO signals used for distribution to cable systems. Early setups were very expensive and large, with 12-foot dishes. Many were motorized, allowing for reception of multiple satellites, and therefore a greater selection of channels. Originally, all channels were available in the clear, including premium movie services, a major draw and source of growth for the then-burgeoning industry. In 1986, movie channel HBO encrypted their signal, setting a precedent for most other mainstream cable television services. This led to a major decline in the sales of satellite systems. By the early 1990's, the industry recovered as a result of Videocipher decoders being bundled with systems. TVRO systems reached their peak around 1995 before declining as a result of consumer adoption of higher-powered, "small-dish" systems such as Dish Network. As of May 31, 2005, 215,076 big dishes were still subscribed to pay TV programming, as opposed to nearly three million at the peak in 1995, although more may be in use solely for free-to-air television reception. [
1].
Satellites used for television signals are generally in either highly-elliptical (with inclination of +/-63.4 degrees and orbital period of about 12 hours) or geostationary orbit 37,000 km (22,300 miles) above the earth's
equator.
Satellite television, like other communications relayed by satellite, starts with a transmitting antenna located at an
uplink facility. Uplink satellite dishes are very large, as much as 9 to 12 meters (30 to 40 feet) in diameter. The increased diameter results in more accurate aiming and increased signal strength at the satellite. The uplink dish is pointed toward a specific satellite and the uplinked signals are transmitted within a specific frequency range, so as to be received by one of the transponders tuned to that frequency range aboard that satellite. The transponder 'retransmits' the signals back to Earth but at a different frequency band (to avoid interference with the uplink signal), typically in the
C-band and/or
Ku-band. The leg of the signal path from the satellite to the receiving Earth station is called the
downlink.
A typical satellite has up to 24 transponders for a C-band only satellite and up to 32 for K
u-band, or more for hybrid satellites. Typical transponders each have a bandwidth of about 36 to 50 Mbit/s. Each geo-stationary C-band satellite needs to be spaced 2 degrees from the next satellite (to avoid interference). For K
u the spacing can be 1 degree. This means that there is an upper limit of 360/2 = 180 geostationary C-band satellites and 360/1 = 360 geostationary K
u-band satellites. C-band transmission is susceptible to terrestrial interference while K
u-band transmission is affected by
rain (as water is an excellent absorber of microwaves).
The downlinked satellite signal, quite weak after travelling the great distance (see
inverse-square law), is collected by a
parabolic receiving dish, which reflects the weak signal to the dish's focal point. Mounted on brackets at the dish's focal point is a device called a
feedhorn. This feedhorn is essentially the front-end of a
waveguide that gathers the signals at or near the focal point and 'conducts' them to a
low-noise block downconverter or LNB. The LNB converts the signals from
electromagnetic or
radio waves to electrical signals and shifts the signals from the downlinked C-band and/or K
u-band to the
L-band range. Direct broadcast satellite dishes use an LNBF, which integrates the
feedhorn with the LNB. (A new form of
omnidirectional satellite antenna, which does not use a directed parabolic dish and can be used on a mobile platform such as a vehicle, was recently announced by the
University of Waterloo. [
2])
The L band signal, now amplified, travels to a satellite receiver box, typically through
coaxial cable (RG-6 or RG-10, etc.; cannot be standard RG-59). The satellite receiver then converts the signals to the desired form (outputs for television, audio, data, etc.). Sometimes, the receiver includes the capability to
unscramble or
decrypt; the receiver is then called an
Integrated receiver/decoder or IRD.
Analog television distributed via satellite is usually sent scrambled or unscrambled in
NTSC,
PAL, or
SECAM television broadcast standards.
If the signal is a digitized television signal or multiplex of signals, it is typically
QPSK.
In general, digital television, including that transmitted via satellites, are generally based on open standards such as
MPEG and .
The encryption/scrambling methods include
BISS,
Conax,
Digicipher,
Irdeto,
Nagravision,
PowerVu,
Viaccess,
Videocipher, and
VideoGuard. A large number of these schemes are known to be ineffective, however.
There are three primary types of satellite television usage: reception direct by the viewer, reception by local television affiliates, or reception by
headends for distribution across terrestrial
cable systems.
Direct to the viewer reception includes
direct broadcast satellite or DBS and
television receive-only or TVRO, both used for homes and businesses including hotels, etc.
Direct broadcast via satellite
Direct broadcast satellite, (DBS) also known as "
Direct-To-Home" is a relatively recent development in the world of television distribution. "Direct broadcast satellite" can either refer to the communications satellites themselves that deliver DBS service or the actual television service. DBS systems are commonly referred to as "mini-dish" systems. DBS uses the upper portion of the K
u band.
Modified DBS systems can also run on C-band satellites and have been used by some networks in the past to get around legislation by some countries against reception of K
u-band transmissions.
DBS systems are generally based on proprietary transport stream encoding and/or
encryption requiring proprietary reception equipment. Service providers sometimes license several manufacturers to provide equipment capable of receiving the proprietary streams. This equipment typically uses a
smart card as part of the decryption system or
conditional access. This measure assures satellite television providers that only authorised, paying subscribers have access to Pay TV content but at the same time can allow
free-to-air (FTA) channels to be viewed even by the people with standard equipment available in the market.
Television receive-only
Television receive-only, or TVRO, refers to satellite television reception equipment that is based primarily on open standards equipment. This contrasts sharply with direct broadcast satellite, which is a completely closed system that uses proprietary reception equipment. TVRO is often referred to as "big dish" satellite television.
TVRO systems are designed to receive analog and digital
satellite feeds of both
television or audio from both C-band and K
u-band
transponders on
FSS-type satellites. TVRO systems tend to use larger rather than smaller satellite dish antennas, since it is more likely that the owner of a TVRO system would have a C-band-only setup rather than a K
u band-only setup. Additional receiver boxes allow for different types of digital satellite signal reception, such as DVB/MPEG-2 and
4DTV.
The narrow beam width of a normal parabolic satellite antenna means it can only receive signals from a single satellite at a time.
Simulsat is a quasi-parabolic satellite earthstation antenna that is capable of receiving satellite transmissions from 35 or more C- and K
u-band satellites simultaneously.
Direct broadcasting satellites which can be received by what are known in Chinese as
little ears have had a major role in breaking the government monopoly of information on
Mainland China. Although met with frequent and generally unsuccessful efforts to regulate them, these small satellite dishes are fairly common in urban China. Satellite television has also played an important role in broadcasting to expatriate communities such as Arabs, and
overseas Chinese.
Africa
South African-based
Multichoice's
DStv is the main digital satellite television provider in sub-Saharan Africa, broadcasting principally in
English, but also in
Portuguese,
German and
Afrikaans.
Canal Horizons, owned by
France's
Canal Plus, is the main provider in
French-speaking Africa. Satellite television has been far more successful in Africa than cable, primarily because the infrastructure for cable television does not exist and would be expensive to install since majority of Africans cannot afford paid cable television. Furthermore, maintaining a cable network is expensive due to the need to cover larger and more sparesly populated areas though there are some terrestrial pay-TV and
MMDS services.
The Americas
Canada
In
Canada, the two legal DBS services available are
Bell Canada's
ExpressVu and
StarChoice. The
CRTC has refused to license American satellite services, but nonetheless hundreds of thousands (up to a million by some estimates) of Canadians access or have accessed American services [
3] â€" usually these services have to be billed to an American address and are paid for in
U.S. dollars. Whether such activity is
grey market or
black market is the source of often heated debate between those who would like greater choice and those who argue that the protection of Canadian firms and Canadian
culture is more important.
Most recently
as of 2004, an October 2004 ruling by judge Danièle Côté of
Québec has determined Canada's
Radiocommunication Act to be in direct violation of the
Canadian Charter of Rights and Freedoms; the judgement gave the federal government a one-year deadline to remedy this breach of the Constitution as the fundamental law of the land. However this goes contrary to prior
Supreme Court of Canada decisions and will likely be appealed.
In addition, Canadian satellite providers continue to be plagued by the unquestionably black market devices which "pirate" or "steal" their signals as well as by a number of otherwise completely lawful devices which can be reprogrammed to receive
pirate TV.
One
cable TV CEO (Karl Péladeau of
Québecor, which owns
Vidéotron) is on public record as demanding conditions be placed on the CRTC license issued to
Bell ExpressVu, due to BEV's reputation for vastly inferior security compared to its cable rivals and
Shaw Cableâ€"owned StarChoice.
Although there are no official statistics, the use of American satellite services in Canada appears to be declining
as of 2004.
Some would claim that this is probably due to a combination of increasingly aggressive police enforcement and an unfavourable
exchange rate between the
Canadian and U.S. currencies. As the U.S. dollar has been declining
as of 2005 versus other international currencies, the decline in DirecTV viewership in Canada may well be related not to a cost difference as much as to the series of smart card swaps which have rendered the first three generations of DirecTV access cards (F, H and HU) all obsolete.
Latin America
Latin America's main satellite system are
SKY Television, which has up to one million subscribers in
Brazil and
Mexico and
DirecTV Latin America, which provides service to the rest of the
Americas. Pay-TV is not popular among Latin American TV viewers and fees are expensive in
PPP terms.
United States
Consumer satellite television reception began in the
United States in the early 1980s with the introduction of the first home satellite systems designed for receiving the same TVRO signals used for distribution to cable systems. Early setups were very expensive and large, with 12-foot (3.7 m) dishes common. Many were motorized, allowing for reception from multiple satellites, and therefore a greater selection of channels. Originally, all channels were available in the clear, including premium movie services, a major draw and source of growth for the then-burgeoning industry. In 1986, movie channel
HBO encrypted their signal, setting a precedent for most other mainstream
cable television services. This led to a major decline in the sales of satellite systems. By the early 1990s, the industry recovered as a result of
Videocipher decoders being bundled with systems. TVRO systems reached their peak around 1995 before declining as a result of consumer adoption of higher-powered, "small-dish" systems such as
DirecTV,
Primestar, and the
Dish Network. As of
May 31,
2005, 215,076 big dishes were still subscribed to pay TV programming
1, as opposed to nearly three million at the peak in 1995, although more may be in use solely for
free-to-air television reception.
Hughes's DirecTV, the first high-powered DBS system, went online in 1994 and was the first
North American DBS service; it is now owned by News Corporation. In 1996,
EchoStar's
Dish Network went online in the
United States and has gone on to similar success as DirecTV's primary competitor. Dominion Video Satellite Inc.'s
Sky Angel also went online in the United States in 1996 with its DBS service geared toward the faith and family market. It has since grown from six to 36 TV and radio channels of family entertainment, Christian-inspirational programming and 24-hour news. Dominion, under its former corporate name Video Satellite Systems Inc., was actually the second from among the first nine companies to apply to the FCC for a high-power DBS license in 1981 and is the sole surviving DBS pioneer from that first round of forward-thinking applicants. In 2004,
Cablevision's
Voom service went online, specifically catering to the emerging market of
HDTV owners and aficionados, but folded in April 2005, with the service's "exclusive" high-definition channels currently being migrated to the Dish Network system. Commercial DBS services are the primary competition to
cable television service, although the two types of service have significantly different regulatory requirements (for example, cable television has
public access requirements, and the two types of distribution have different regulations regarding carriage of local stations).
The majority of
ethnic-language broadcasts to North America are carried on K
u band free-to-air; the largest concentration of ethnic programming is on Intelsat Americas 5 at 97° W.
GlobeCast World TV offers a mix of free and pay-TV ethnic channels in the internationally-standard
DVB-S format, as do others.
Home2US Communications Inc. also offers ethnic programming, the platform is on AMC-4 at 101° W, with several ethnic channels as well as free and pay-TV. Several U.S.-English language network affiliates (representing
CBS,
NBC,
ABC,
PBS,
Fox,
WB,
i and
UPN) are available as free-to-air broadcasts, as are the three U.S.-Spanish language networks (
Univisión,
Telefutura and
Telemundo). The number of free-to-air specialty channels is otherwise rather limited. Specific FTA offerings tend to appear and disappear rather often and typically with little or no notice, although sites such as
LyngSat do track the changing availability of both free and pay channels worldwide.
Asia
Malaysia
Malaysia's sole satellite television operator, Measat Broadcast Network Systems (a subsidiary of
Astro All Asia Networks plc) launched
Astro in
1996. It currently holds exclusive rights from the Malaysian government to offer satellite television broadcasting services in the country through the year 2017.
Japan
NHK started experimental broadcasting TV program using BS-2a satellite on May, 1984. After these successful experiments, NHK started regular service (NTSC) and experimental
HDTV broadcasting using BS-2b on June, 1989. On April, 1991, Japanese company
JSB started pay TV service while BS-3 communication satellite was in use. In 1996 total number of households that receive satellite broadcasting exceeded 10 million.
The modern two satellite systems in use in Japan are
B-SAT and
JSAT; the
BS digital service uses B-SAT, while
SKY PerfecTV! uses JSAT.
India
India has the indigenously built
INSAT series satellites from
Indian Space Research Organisation (
ISRO) alongwith some private operators [
4] . INSAT-2E, INSAT-3C and INSAT-3E carry multiple channels for Indian television viewers. Thaicom-2 and Telstar 10 are the other major private satellites over India. Notable service providers offering a bouquet of multiple channels are state-owned
Doordarshan,
News Corporation owned
STAR TV and
Sony owned
Sony Entertainment Television.
Middle East & North Africa
The
Middle East has a high penetration of homes receiving TV channels via DTH satellite. One of the pioneers of
free-to-air digital satellite television is considered to be
MBC, which began broadcasting in
c band through Arabsat and is the first network in the world to offer a free-to-air Western based English language movie channel to the Middle East audience via its spinoff channel
MBC 2. Its direct rival is considered to be
Dubai, UAE based
One TV, earlier called Channel 33, which was the first channel in the Middle East to provide English language general entertainment programming for the expatriate community.
The first digital DTH pay-TV network to provide Western Entertainment was
Orbit Satellite Television and Radio Network broadcasting via
Arabsat (
C band), later on
Showtime Arabia a joint venture between
Viacom (21% stake) and
KIPCO (79% stake) started broadcasting, via
PanAmSat (
C band), but later switched over to
Nilesat (
KU band).
Arab Radio & Television (ART) now known as
Arab Digital Distribution although a late comer, gained ground by broadcasting exclusive sports events.
These networks can be easily received via 60cm to 180cm satellite dishes. Most of the popular channels are transmitting from these satellites and orbital positions:
Arabsat at 26°E,
Asiasat at 100.5°E and 105.5°E,
Eutelsat Hot Bird at 13°E,
Nilesat at 7°W, and
PanAmSat at 68.5°E.
Lyngsat satellite charts prove, the Middle East enjoys the highest number of FTA digital satellite channels in the world, with
One TV and
MBC 2 airing blockbuster movies like
The Lord of the Rings film trilogy without any
encryption.
Australasia
Satellite television in
Australia has proven to be a far more feasible option than cable television, due to the vast distances between population centres. The first service to come online in Australia was
Galaxy Television, which was later taken over by Cable Television giant
Foxtel, which now operates both cable and satellite services to all state capital cities (except Darwin and Hobart) and the whole of Western Australia. Its main metropolitan rival was
Optus Vision, while rural areas are served by
Austar, both of which just rebroadcast Foxtel as of 2005.
In
New Zealand,
SKY Network Television offers multichannel digital satellite TV, in addition to its terrestrial
UHF service. The upcoming
FreeView service will also be available on satellite.
Europe
Continental Western Europe
In Europe, DBS satellite services are found mainly on
Astra satellites and
Hotbird (operated by
Eutelsat), with
Sky Italia,
Canal Digitaal and
UPC being the main providers in
Italy,
Western Europe and
Central Europe.
BSkyB (known as Sky) also serves
Northern Europe and many channels can be received as far away as
Cyprus.
The overall market share of DBS satellite services in 2004 was 21.4% of all TV homes, however this highly varies from country to country. For example, in Germany, with many free-to-air TV-stations, DBS market share is almost 40%, and in Belgium and the Netherlands, it's only about 7%, due to the widespread cable networks with exclusive content.
Russia
Since creation of its national network of satellite television in 1967, Russian satellite broadcasting service based on powerful geostationary buses which provide mostly free-to-air television channels to millions of householders.
Pay-TV is not popular among Russian TV viewers and only the
NTV Russia news company has a few encrypted channels.
United Kingdom
The first commercial DBS service in the
United Kingdom,
Sky Television, was launched in 1989, providing 4 analogue TV channels. In the following year
BSB was launched, broadcasting five channels in
D-MAC format; the two services subsequently merged to form
British Sky Broadcasting. In 1994 17% of the group was floated on the
London Stock Exchange (with
ADRs listed on the
New York Stock Exchange), and
Rupert Murdoch's
News Corporation owns a 35% stake.
By 1999, following the launch of several more satellites (at 19.2°E by
SES Astra, the number of channels had increased to around 60 and BSkyB launched the first subscription-based digital television platform in the UK, offering a range of 200 channels broadcast from the Astra satellites at 28.2°E under the brand name
Sky Digital. BSkyB's analogue service has now been discontinued, with all customers having been migrated to Sky Digital.
Nordic countries
The first satellite service specifically set to the Nordic region was
TV3 which launched in 1987. With the launch of
Astra 1A, getting the TV3 channel got easier. The first Nordic-specific satellite,
Tele-X, was launched in 1989. The services directed at Scandinavia were then scattered among several satellites. In 1993, the former BSB satellites were bought by a Swedish and a Norwegian company, respectively. These two satellites were renamed
Thor 1 and
Sirius 1, moved to new positions and started broadcasting services intended for people in the Nordic region. With the launch of additional Thor and Sirius satellites later in the 1990s, Astra and other satellites were abandoned by the Nordic services with almost all Nordic satellite television migrating to the Sirius and Thor satellites.
Initially the basic channels were
free-to-air. This caused several rights problems since viewers throughout Europe were able to see very much acquired English language programming as well as sports for free on the Nordic channels, although the channels only held broadcasting rights for specific countries. One way of avoiding that was to switch from
PAL to the
D2MAC standard, hardly used anywhere outside the Nordic region. An unencrypted channel could still be seen in all the Nordic satellite homes, so eventually all channels went encrypted (several of them only being available in one country).
There are two competing satellite services:
Canal Digital (Norwegian
Telenor) and
Viasat (
Kinnevik). Canal Digital launched in 1997 and was digital from the start, broadcasting from Thor. Kinnevik had been operating an analogue subscription service since the late 1980s, but waited until the year 2000 before launching a digital service. All analogue services from Thor and Sirius will have ceased in 2006, when the three remaining Danish channels go digital-only. The competition between Viasat and Canal Digital has caused some homes in Scandinavia to have to buy two set-top boxes and have two subscriptions to get the full range of channels. Viasat doesn't provide their own channels (TV3, TV3+, ZTV, TV1000 and the Viasat-branded channels) on the Canal Digital platform. Canal Digital does however have exclusive distribution of channels from
SBS Broadcasting,
Discovery,
TV2 Denmark and
Eurosport; for several years the Swedish
SVT and
TV4 channels were also exclusive to Canal Digital.
*
Satellite dish*
Microwave antenna*
Commercialization of space*
Satellite Terminology and Glossary*
Lyngemark Satellite Charts*
Broadcast Engineering*
C-Band FAQ List*
Satellite TV in Thailand*
Linowsat PID-Lists and Videobitrate Charts*
How satellite tv works
